Here's The Official Cost of Sending a Letter to Mars

That's a whole lot of stamps.

DAVID NIELD

18 DEC 2015

While NASA works out the logistics of getting human beings to Mars, the rest of us have other questions on our minds: like how much it would cost to post a letter to the Red Planet? Okay, so using snail mail to communicate with Mars's very first residents isn't exactly the most efficient way of keeping in touch, but it does give us some healthy perspective on just how far away it is.

The question was posed by a five-year-old British boy, Oliver Giddings, to the Royal Mail - the official postal service of the United Kingdom. Eager to get Oliver an answer, the Royal Mail team consulted with experts at NASA to assess the distance the letter would have to travel, and the amount of fuel required to reach Mars. They also had to figure out the price of the stamps needed to send a 100-gram letter to one of NASA's bases, which will eventually be transportated to a site on Mars.

The official answer: £11,602 and 25 pence - so about US$17,427. That's a hefty sum, but it's not completely out of this world. NASA says it cost around US$700 million to send the Curiosity rover to Mars, and considering the letter will be travelling at least 56 million km (depending where Earth and Mars are in their orbits at the time), £11k begins to look like pretty good value. You might have missed the last post for this Christmas, however.

"The team reached a conclusion about the price, based on the information NASA provided and Royal Mail’s current pricing," Royal Mail senior customer advisor Andrew Smout explained in his reply to Oliver. "[Spaceship] storage is at a premium... Fuel is very expensive and affects the cost of sending letters around our planet. At the moment, the cost of sending a letter to the US by a jumbo jet is more than sending it to France, because it’s much further away."

Based on the Royal Mail's current pricing, the letter would need 18,416 First Class stamps, or 21,486 Second Class stamps attached to it. Or, more realistically, a special Mars stamp of the equivalent value.

Oliver's mum said he was "so excited" to get a response from the company. "Thank you for working out the answer, I enjoyed reading it," Oliver wrote back. "It’s very expensive to send a letter to Mars. You would need so many stamps!"

"We always like to answer every query we get from our customers," added Smout. "This one took a bit longer but we enjoyed the journey to find out!"

Now the cost of an interplanetary postal service has been calculated, we can return to the more complicated business of setting foot on Mars. NASA recently put out a call for astronauts to join the first manned missions to Mars, which are currently scheduled to take place some time during the 2030s.